Safety latch for luminaires



Sept. 10, 1968 E. R. JABLONSKI 3,400,963.

\ SAFETY LATCH FOR LUMINAIRES Filed Feb. 13, 1967 2 Sheets-Sheet 1 Q- 7 ze? mlm faz/warez A. JZOmSA/J Sept. l0, 1968 E. R. JABLONSKI 3,400,963

SAFETY LATCH FOR LUMINAIRES Filed Feb. 13, 1967 2 Sheets-Sheet 2 iwf/@anton award A. c/Zoms/Q' United States Patent O ABSTRACT F THE DISCLOSURE A luminaire having an open-bottomed housing and a bottom closure member which is hingedly mounted at one side to the housing and secured at its other side by a latch assembly consisting of an overcenter latch member pivotally connetced to a resilient tension spring member which is, in turn, pivotally connected to the closure member. The latc'h member has a first catch engaging portion for fully latching the bottom closure member in its closed position and a second catch engaging portion which is engageable as the latch member is moved from its fully latched position towards its open position to a stable intermediate position for locking the bottom closure member in its stable, fully closed position prior to movement of the latch member and closure member to their fully open positions.

Background of the invention One type of outdoor luminaire employs a generally horizontally disposed gaseous discharge lamp and includes an open-bottomed housing provided with a bottom closure member hingedly mounted at one side to the housing and latched thereto at the other side. Luminaries of this type also include an optical assembly which generally com prise a reflector mounted in the housing and a relatively heavy refractor removably mounted on the bottom closure member. The latch assemblies of such art luminaires are generally of the spring loaded pivotal latch or spring toggle types. These latching assemblies have not been wholly satisfactory, however, because they occasionally open accidentally as the result of vibrations, wind or because they were not fully latched when the luminaire is closed. This has resulted in the relatively heavy refractor, or the closure door or both, falling away from the luminaire and thereby creating a hazardous situation which has resulted in a number of serious injuries. Another shortcoming of such prior art luminaire latches is that it is extremely diiiicult, if not impossible, to determine from ground level whether the bottom closure member is ajar or incompletely latched.

Summary of the invention The invention comprises a luminaire having an openbottomed housing and a bottom closure member secured in a closed position thereto by an overcenter latch as- Sembly which includes a stationary latch means and a movable latch means mounted for movement between a fully latched and a fully opened position relative to the stationary latch means, one of the latch means having a first latch portion for being operatively engaged when the movable latch means is in its fully latched position and a second latch portion operatively engaged when the movable latch means is in an intermediate position between its fully latched and fully opened positions, the second latch portion supporting the bottom closure member in a stable, fully closed position. The latch assembly includes a tension spring member pivotally connected between the stationary latch means and the movable latch means.

The latch assembly therefore may be described as a double overcenter device in that the assembly provides a fully closed position in which the first latch portion is operatively engaged, an intermediate position in which the movable latch means is in an intermediate position in which both the first and second latch means are opera tively engaged and in which intermediate position the closure member is supported in a stable, fully closed position, and iinally, a fully open position in which the closure member is permitted to open.

Brief description of the invention FIG. 1 is a side elevational view, with parts broken away, of a luminaire incorporating a latch assembly according to the instant invention;

FIG. A2 is an enlarged, fragmentary, sectional view, showing the latch mechanism illustrated in FIG. l;

FIG. 3 is a view taken along lines 3--3 of FIG. 2;

FIG. 4 shows the latch mechanism of FIG. 2 in its intermediate latched position; and v FIG. 5 shows the latched mechanism of FIG. 2 in its unlatched position.

Preferred embodiment of the invention FIG. l shows a gaseous discharge type luminaire 10 which includes a generally inverted ovate housing 11 having an elongate portion 12 integrally formed at one side thereof for enclosing a slipfitter assembly (not shown) which permits attachment of the luminaire 10 to a horizontally extending pipe support member 17.

It will be appreciated by those skilled in the art, that a generally ovate rellector 13 may be disposed within the housing 11 for reecting light rays in a generally downward direction, as viewed in FIG. l, whereupon they may be further modified by a cooperating refractor 14. The refractor 14 is mounted on a bottom closure member 15 which is supported at one end beneath the sliptter housing 12 by a hinge assembly 16 to permit pivotal movement in a clockwise direction, as viewed in FIG. 1, so that the underside of the housing may be exposed for relamping, the removal of the reflector 13 from the housing 11, the removal of the refractor 14 from the bottom closure member 15 or other maintenance purposes.

A latch assembly 18 is provided at the opposite side of the closure member 15 so that the latter may be affixed in its closed position, shown in FIG. l, whereby a peripheral flange 20 on the refractor 14 is held in cooperative sealed engagement with the peripheral flange 21 of the reliector 13 and the upper peripheral rim 22 of the closure member 15 is held in registry with lower rim 23 of the housing 11.

The peripheral ange on the refractor member 14 engages the rim of a correspondingly shaped aperture 24 formed in the bottom closure member 15 wherein the refractor is supported thereon. As those skilled in the art will appreciate, spring latch members (not shown) may be provided for securing refractor 14 in aperture 24.

The details of the luminaire 10 form no part of the instant invention and, accordingly, have been discussed in general terms for the sake of brevity. For a more complete description of Va luminaire of this type, reference is made to U.S. Patent 3,204,092, issued Aug. 31, 1965, and assigned to the assignee of the instant invention.

It will be appreciated that, should the latch assembly 1-8 open accidentally, the bottom closure member 15 will -swing downwardly about the hinge 16 and hang in an open position wherein the refractor 14 may become dislodged or the `bottom closure member may breakaway from the housing 11 at the hinge 16. Serious injury has resulted from the refractor 14 and/or bottom closure member 15 falling away in this manner. This is especially apt to hap pen in larger size-d luminaires wherein the refractors 14 are made of relatively heavy glass inasmuch as their op erating temperatures are too high to permit the useof plastic refractors. The safetylatch assembly 18, according't the instantY invention, vis"constructed and arranged to prevent accidental opening of the bottom closure member and, `in addition, to provide a visual indication from ground level when the luminaire is partially unlatched.'

The latchassembly 18 is shown in FIGS. 2-5 to include a movable latch member 26 and a latch spring 27 mounted on the Ibottom closure memebr 15 and a stationary latch portion or catch 28 on the housing 11.

The latch spring 27 is shown in FIGS. 2 and 3 to include a pair of generally U-shaped side portions 29 which are joined at their upper ends by a linear, generally horizontal cross portion 30. Each of the side portions 29 terminates at its lower end in an outwardly extending linger 32 which engages a suitable aperture 33 provided in each of a pair of spaced parallel ears 35 integrally formed on the bottom closure member 15 beneath the stationary latch portion 28 on the housing 11. In the free form of the spring 27 the side portions 29 are not parallel, as L shown in FIG. 3, but their lower ends bow outwardly to provide spring pressure to hold the ears 32 in the apertures 3'3.`

The stationary catch 28 comprises an elongate, generally linear, convex-in-cross-section tongue 37 formed integrally on the upper surface of an outwardly extending -rim 38 on the housing 11. Catch 28 also includes a generally linear, concave arcuate surface 40 formed on the rim 38 inwardly of and adjacent to the tongue 37 and coextensive therewith. In addition, a coextensive shoulder 41 is formed at the outer edge of the rim 38 and adjacent the tongue 37.

The latch member 26 is generally elongate and of a size to ft between the side portions 29 of the latch spring 27. In addition, the latch member 26 includes a lower latch portion 42 which has a generally linear, elongate, arcuatein-cross-section foot 43 formed at its lower end and a lgenerally linear, elongate, concave-in-cross-section groove 45 formed above and adjacent to the foot 43. As will be pointed out more fully hereinbelow, the foot 43 and the groove 45 on the latch member 26 are complementary to the tongue 37 and the surface 40, respectively, on the catch portion 28. An elongate circular slot 46 is formed in the back of the latch portion 42 for receiving the spring c-ross portion 30.

The latch member 26 also includes a generally upwardly extending handle 47 which terminates at its upper end in an inwardly extending finger grip 48. A plurality of longitudinally extending V-shaped grooves 48 may be formed in the upper and lower surfaces of the finger grip 48 to improve the gripping action therewith. The juncture Ibetween the groove 45 and the handle 47 forms a knee 50.

Reference is now made to FIG. 2 which shows the latching assembly 18 in its fully latched position. Here rit can be seen that the upper rim 22 of the bottom closure member 15 is held in engagement with the lower edge 23 of the housing 11 and the peripheral ange 21 on the reector 13 is held in sealing engagement with the ange 20 on the refractor 14. This latching force is provided 'by the ilexure of latch spring 27, whose lower end engages the bottom closure 15 and whose upper end engages the latch member 26 to resiliently urge the rim 22 of closure member 15 against the lower edge 23 of housing 11 as foot 43 is held against the complementary arcuate surface 40 on the housing 11.

It can be seen in FIG. 2 that the line of action of the spring 27 is above the point of engagement between the latch member 26 and the surface 40. As a result, the latch member 26 and the spring 27 act as a toggle tending to collapse the member 26 clockwisein FIG. 2. This action tends to hold the member 26 in its fully latched position. In addition, the engagement between the foot 43 and the tongue 37 formed on the housing 11 retains the lower end of latch member 26 in position.

When it is desired to release the latch 18 and open the *bottom closure member 15, the operator grips the grooves 49 on the hand grip 48 and pivots the latch member 26 clockwise, as viewed in FIG. 2, and to its position shown in FIG. 4, as the foot 43 of latch portion 42 slips on the arcuate surface 40. As the latch member 26 pivots, it will again reach an overcen'ter position relative to the spring 27 so that'it will then snap into its position shown in FIG. 4.

The latch member 26 is shown in its intermediate position in FIG. 4 wherein the tongue 37 on the housing 11 is disposed within .the groove 45 formed in the latch member 26 and wherein the foot 43 of said latch member is disposed at the junction between the tongue 37 and the arcuate surface 40. The spring 27 is still flexed to tightly hold the peripheral rim 22 of the bottom closure member 15 against the lower peripheral rim 23 of the housing 11.

It can Ithus be seen that when the latch member 26 is in its intermediate position, shown in FIG. 4, the bottom closure member 15 remains in its fully closed position. In addition, the engagement between the tongue 37 and the groove 45 and the toggle action of the spring 27 prevents dislodgment of the latch member 26 so that the intermediate latched position shown in FIG. 4 is stable and can safely hold the bottom closure member 15 in its fully latched position.

In order to fully release the latch assembly 18, the latch member 26 is pivoted clockwise, as viewed in FIG. 4, as the knee 50 is rocked on the shoulder 41. This moves the latch member 26 from its position shown in FIG. 4 to its position shown by full lines in FIG. 5 to disengage the groove 45 from the tongue 37. The latch member 26 may then be moved horizontally from its position shown by full lines in FIG. 5 to its position shown by phantom lines wherein the latch member is moved clear of the housing 11. The hand grip 48 provides a convenient handle for moving the latch member 26 from its full to its phantom position in FIG. 5, and for lowering the bottom closure member into its fully open position.

When the bottom closure member is to be reclosed, the underside of the hand grip is again grasped by the operator, and the bottom closure member 1S is raised until its peripheral rim 22 engages the bottom edge 23 of the housing 11, whereupon the knee 50 on the latch member 26 is engaged on the shoulder 41 of the housing 11, as shown by full lines in FIG. 5. The toggle action of the spring 27 will then tend to snap the groove 45 downwardly against the tongue 37 to hold the bottom closure member in position as the latch assembly 18 assumes its intermediate position shown in FIG. 4. The latch assembly may then be placed in its fully latched position by rotating the latch member 26 counterclockwise, as viewed in FIG. 4, until the latch member reaches an overcenter position relative to the spring 27, whereby it will be snapped into its fully latched position shown in FIG. 2.

It can be seen from the foregoing that the latch assembly 18 has a stable latched position, shown in FIG. 4, which is between its fully latch position shown in FIG. 2 and its unlatched position shown by phantom lines in FIG. 5. Thus, if the latch assembly 18 should accidentally become dislodged from its fully latched' position shown in FIG. 2, or if it should not be fully moved into this latched position, it 'will assume its intermediate latched position shown in FIG. 4 wherein the bottom closure member 15 is prevented from falling open to create a safety hazard. In addition, because the latch member 26 extends outwardly when it is in its intermediate latched position seen in FIG. 4, this can be readily seen from ground level so that the assembly may be returned t0 its fully latched position.

While only a single embodiment of the invention has been illustrated and described, other modicationstheref of will become apparent to those skilled in the art once the inventive concept is known. Accordingly, it is not intended to limit the invention to the foregoing description, but only by the scope of the appended claims.

l claim:

1. in a luminaire having an open-bottomed housing and a bottom closure member, latch means for securing the bottom closure member in a fully closed position and including a stationary latch means and a movable latch means mounted for movement between a fully latched and a fully open position relative to said stationary latch means, one of said latch means also having a first latch portion for being operatively engaged when the movable latch means is in its fully latched position and a second latch portion operatively engaged when the movable latch is in an intermediate position between said fully latched posi-tion and said fully open position, said second latch portion supporting said bottom closure member in a stable fully closed position.

2. The luminaire set forth in claim 1 wherein said stationary latch means is mounted on one of said housing and bottom closure member and said movable latch means is mounted on the other one thereof.

3. The luminaire set forth in claim 2 wherein said movable latch means includes a latch member and resilient means for resiliently urging said latch member into high pressure engagement with said stationary latch means in each of its fully latched and intermediate positions.

4. The luminaire set forth in claim 3 wherein said latch member and said resilient means comprise a resilient overcenter assembly which is in an overcenter condition when said movable latch means is in each of its fully latched and intermediate positions.

5. The luminaire set forth in claim 2 wherein said iirst and second latch portions are disposed on said movable latch means, said irst and second latch portions being successively engaged with said stationary latch means when said movable latch means is moved from its fully latched to its intermediate position.

6. The luminaire set forth in claim 5 wherein said movable latch means comprises a latch member and spring means, said latch member and said spring means comprising a resilient overcenter assembly which is in an overcenter condition when said movable latch means is in each of its fully latched and intermediate positions.

7. The luminaire set forth in claim 6 wherein said stationary latch means includes protruding means eX- tending from said housing, said first and second latch means each successively engaging said protruding means when said movable latch means is moved from its fully latched to its intermediate position.

8. The luminaire set `forth in claim 7 wherein said second latch portion is generally recessed to embrace said protruding means, said latch member pivotally engaging said housing for pivotal movement against said spring means when said latch member is in its intermediate position so that said latch member may be pivoted on said housing to move said second latch portion out of engagement with said protruding means.

9. The luminaire set lforth in claim 1 wherein said stationary latch means is mounted on said housing and said movable latch means is mounted on said bottom clo- CII sure member, and wherein said movable latch means in cludes a latch member and resilient means for resilientl; urging said latch member into high pressure engagemen with said stationary latch means in each of its fully latchet and intermediate positions, said lirst and second latcl portions being disposed on said movable latch member said first and second latch portions being successively en gaged with said stationary latch means when said movablt latch means is moved from its fully latched to its inter mediate position.

10. The luminaire set forth in claim 9 wherein sait resilient means comprises elongate spring means having one end pivotally engaging said Ibottom closure mem-bei and another end pivotally engaging said latch member.

11. The luminaire set forth in claim 1t) wherein sait` first latching portion is disposed adjacent one end of saic` latch member and said second latching portion is disposed intermediate the ends thereof.

12. The luminaire set forth in claim 11 wherein said spring means engages said latch memlber between said first latching portion and the opposite end of said latch member, said latch member and said spring means comprising a resilient overcenter assembly which is in an overcenter condition when sai-d movable latch means is in each of its fully latched and intermediate positions.

13. |Ilhe luminaire set `forth in claim 12 wherein said stationary latch means includes protruding means extending from said housing, said rst latch portion engaging said protruding means when said latch member is in its fully latched position, said latch member being pivotally mounted on said housing adjacent said protruding means to move said second latch poition into engagement with said protruding means.

14. The luminaire set -forth in claim 13 wherein said second latch portion is generally recessed to embrace said protruding means, said latch member pivotally engaging said housing at a point on said latch member between said second latch portion and the opposite end thereof when said latch member is in its intermediate position so that said latch member may 'be pivoted on said housing and against said spring means 4to move said second latch portion out of engagement with said protruding means.

15. The luminaire set forth in claim 14 and including handle means formed on the other end of said latch member for pivoting the same out of engagement with said stationary latch means for supporting said bottom closure member when the latter is lowered to an open position.

16. The luminaire set forth in claim 14 wherein said latch ,member extends outwardly from said Vluminaire when in its intermediate position to be visible from below said luminaire.

References Cited UNITED STATES PATENTS 572,257 12/ 1896 Heinemann. 1,331,874 2/1920 Priest. 2,324,356 7/ 1943 Brown 292-257 X 3,025,094 3/ 1962 Buchanan 292-247 X FOREIGN PATENTS 566,738 4/ 1958 Belgium.

RICHARD E. MOORE, Prmiary Examiner. 

